US2547268A - Withdrawable drive shaft and brake assembly for vehicle drive wheels - Google Patents

Description

April 3, 1951 JAcoBl WITHDRAWABLE DRIVE SHAFT AND BRAKE ASSEMBLY FOR VEHICLE DRIVE WHEELS Filed sept. 29, 1948 WAI m, wh

Patented Apr. 3, 1951 seizes WITHDRAWABLE DRIVE SHAFT AND BRAKE ASSEMBLY FOR VEHICLE DRIVE WHEELS Louis Jacobi, Milwaukee, Wis., assigner to Allis- Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Application september ze, 194s, seem No. 51,704

(c1. 1an-75) 7 Claims.

This invention relates generally to braking means and is more particularly directed to a tractor linal drive unit including braking means therefor.

In an agricultural tractor designed to straddle two or more rows of standing erop with the tractor wheels traveling in the space between the rows, it is essential to have a maximum amount ofgroundclearance for that portionoi the rear axle housing adjacent each wheel in order to permit cultivation of a greater height ofstanding crop thus enabling crops, such as corn, to be cultivated throughout a greater portion of the growing period. To provide this clearance it has heretofore been customary in the design and manufacture of tractors to either (1) use an extremely large diameter rear wheel which in-V oreasesthe cost of the tractor considerably', or (2,) u 'se a droptype rear axle construction which is also expensive in that additional parts, including gears, must be used, or (3) slenderize the rear axle housing as much as possible by moving the brake mechanism for the rear wheels into close relation with the center line of the tractor. In the construction of the Smaller and less powerful type of agricultural tractors the last mentioned design has been generally found to be the most desirable in that it aifords an economical construction without sacricing operating efficiency. However, this preferred design has heretofore presented a serious service problem in that in order to adjust or repair the brake mechanism it has been necessary7 to remove the wheel and disassemble the inal drive unit up to its point of junction with the diiferential casing before 3 the brake mechanism was sufciently exposed for servicing. f

A solution of this problem is incorporated in the present invention which has for its principal object the provision of a final drive unit having parts, including braking means, constructed and arranged in a novel and improved manner so as to permit the withdrawal oi the rear wheel, axle housing, axle shaft and brake drum, as a unit from the differential casing and brake friction element carried thereby. f It is also an object of this invention toprovide an enclosed rotatable shaft including braking means therefor which are readily accessible for servicing and which unit is simple and compactv in construction, efficient in operation and lends itself to production at a relatively low cost.

The construction and operation oi apparatus capable of accomplishing the above stated objects will become readily apparent as the disclosure progresses and particularly points out various advantages and features considered'of special importance. And accordingly, the present invention may be considered as comprising the various features of construction, combina'- tions and subcombinations of elements or parts as is hereinafter more fully set forth in the detailed description and appended claims, reference being had to the accompanying drawings inV which:

Fig. 1 is a partial plan view of a tractor embodying the present invention, with certain of the enclosed parts thereof shown in dotted lines;

v Fig. 2 is an enlarged sectional view taken along line I-II in Fig. 1; and

Fig. 3 is a view similar to that shown in Fig. 2 with the axle housing unit having been axially moved away from the diiierential casing.

Referring to Fig. 1,-it will be seen that the apparatus chosen to illustrate the present invention comprises generally a tractor l having a rear driving unit 2 and a forwardly extending frame 3. The rear driving unit includes a .transverse final drive housing E having an enlarged central portion E operatively enclosing a conventional differential drive mechanism l and having a pair of oppositely projecting axle shaft housings 8 each enclosing an axle shaft le having its inner end operatively connected with the differential mechanism l. The outer or exposed end of each axle shaft terminates in a radially anged hub portion I I provided with a circular series of circumferentially spaced holes l2 (see Fig. 2) through which are inserted bolts i3 xedly attaching the central disk portion i5 of a driving wheel I6 thereto. The central portion 6 of the final drive housing includesan integral forwardly extending portion` il operatively enclosing a change speed gearing I8 drivingly connected with the differential mechanism this gearing including a power input shaft 2li extending rearwardly Y through the central portion of the final drive housing in overlying relation to the differential mechanism therein and into the adjacent end of a clutch and flywheel housing 2l detachably bolted or otherwise rigidly secured to the rear side of the lin-al drive housing 5 in rearwardly overhanging relation thereto.

A yconventional internal combustion engine power unit 22 is detachably bolted to the rear end of housing 2l and is thereby supported in rearwardly overhanging relation to central portion 6 of nal drive housing 5, the adjacent' end of the engine crank shaft 23 entering housing 2i and having mounted thereon a flywheel andA the 0 clutch element 25. An axially aligned shaft extension mounts a shiftable clutch element selectively engageable w'th a clutch element fixed to engine crank shaft 23 in a conventional manner (not shown), and the shaft extension has mount ed on its end remote from engine 22 a gear 2g which is drivingly connected in a suitable manner (not shown) to a gear 3i positioned on the adjacent end of shaft 2li for rotation ther witl Power is thus transmitted tf. rough this power input shaft to the change speed tran ission is and thence through the diiierential mechanism l to the separate rear axle shafts It. A clut :l element shift collar 32 is provided with an arin which extends through an opening (not shown) in housing 2i and is operatively connected with the rear end of an actuating rod fifi which extends forwardly through a portion the axle housing S and along the adjacent side of the forwardly extending portion il of the iinal drive housing 5 for suitable connection (not shown) with a clutch pedal Se.

The central enlarged portion E of the nal drive housing also encloses brake means 3l and 3B symmetrically arranged witl respect to the longitudinal axis of the forwardly extending portion il enclosing the change speed gearing i8, there being a brake means positioned for asso-- ciation with each axln shaft lll so as to control rotation thereof for braking and turning purposes as is common practice. Each brake means is provided with a separate actuating arm and 4l (see also 2) operatively connected with a forward extending actuating rod or linl; #l2 and d3, these links being positioned adjacent opposite sides of the forwardly extending housing portion Il and having suitable connection (not shown) with separate brake pedals dii and 35.

Referring more particularly to Fig. 2, it may be seen that a conventional differential gearing 'i is employed to transmit power from the transmission output shaft lll (Fig. l) through a ring gear 48, dierential carrier 5%, pinion gears 5l and side gear 52 to axle shaft l5?. find in this connection, it will be noted that ring gear 48 is rotatably mounted in a bearing structure 53 carried by the differential casing by suitable means such as the roller bearing 5S. This bearing structure 53 extends outwardly through an opening (not shown) in the side of the differential casing 55 and includes a `flanged portion 5l' having bolt receiving openingsI (not shown) therethrough, this flange being adapted to abut the adjacent surface of the casing 55 in a manner affording alignment of the openings in the flange with internally threaded bores 5S in the casing so that cap screws el? may be placed in these Aaligned openings to secure bearing structure to differential casing Also, side gear includes an internally splined hollow shaft portion El into which the spl' ed end t2 (see Fig. 3) axle shaft le may .Je thrust to receive pov-.fer from engine 22 transmitted through differential gearing l. In this respect, it should he obvious (see Fig. l) that the opposite or right hand side of the differential includes a sim .r side gear which is mounted in a bearing structure similar to that just described. It is believed that a description of one axle shaft and parts associa-ted therewith is suiicient for a proper understanding of the present invention.

A conventional expansion type brake mechanis-in S3 is detachably secured to the outer por tion of bearing structure by cap screws E5 or the like, in coaxial relation with axle shaft il).

And a bra-ke actuating arm il extends upward therefrom for connection with the brake pedal 4E as previously described. it this point it will be noted that bearing structure 53, brake 63 and the brake actuating means including arm di comprise a unitary structure which he separated from casing 5% by removing cap screws 5e. And, also, that this unitary structure may in turn be separated into its component parts upon removal of cap screws (i5. A brake drum E@ is nonrotatably secured to axle shaft le, as by a key 31, and includes a flanged friction surface E?! positioned in circumferentialiy spaced overlying relation to brake shoe l2. Expansion of brake shoe 'Eil will cause saine to bear against brake drum portion 53 and retard the rotating motion of axle shaft And surrounding brake mechanisms S3, drum Se and axle shaft i9 is an elongated tubular axle housing 8 havinga somewhat enlarged portion il, rectangular in cross section and of relatively short length, enclosing Toi-aire means 33 and hav ing a relatively long narrow portion 'l2 xed thereto, as by welding, and projecting outwardly to the free end of the axle shaft lil. Axle housing 8 is detachably to the side of differential casing 55l in any suitable manner such as by the use of a stud 'i3 and nut l5 as shown in Fig. 2. In this illustration, differential casing 55 has internally threaded bores 'i in the outer side thereof adapted for alignment with openings 'Il and 'i8 in the four corners of rectangular portion 'ii of axle housing 8 and stud i3, threaded at either end, is placed through aligned openings '16, 'il and le and nut 'le is placed on the outer end (see Fig. l) to fixedly secure axle housing 8 to differential casing 55. A roller bearing 80 on the outer end of axle shaft iii maintains the axle in spaced relation t-o that end of the axle housing S and permits rotation of saine relative to the housing. In this respect it will be noted (Fig. 2) that shaft i@ is axially xed relative to housing 8 by oppositely facing shoulder portions 3l and 82, formed on the axle and housing, respectively, which shoulders abut opposite sides of roller bearing 83. And, as previously mentioned, the outer end portion of axle shaft i@ terminates in a hub portion l! to which a wheel disk i5 is secured.

Looking new at Fig. 3, it may be seen that the brake actuating means and the shoe mounted thereon have been exposed by removal of axle housing e from differential casing 55 in a manner now to be described, having in mind from the foregoing description that wheel l, shaft i d, axle housing 8 and brake drum to are all separably interconnected and form a unitary structure to be hereinafter referred to as the axle housing unit. in order to remove this structure from its position ixedly abutting differential casing 55 nuts 'i5 are removed and the axle housing unit is shifted axially away from diiierential casing 55. This movement separates cooperating splined portions G2 and E! of shaft l!) and gear 52, respec -ively, and withdraws the axle housing unit from its supported position on studs '13. As viewed in 3, the axle housing unit has been axially shifted to the left sufficient distance to expose brake shoes lli for repair or replacement and it will be obvious that further movement in this direction will completely separate the axle housing from the tractor.

From the foregoing description, it is apparent that a tractor inal drive constructed in accordance with the present disclosure includes features aording the various advantages hereinabove stated as objects of this invention. More specifically, a unit so constructed providessulcient ground clearance to permit operation of a tractor over rows of standing crops, and also pro-1 vides a readily detachable axle housing unit affording easy access to the brake mechanism which unit is simple and compact in construction, eiilcient in operation and may be produced at a relativelylow cost. l

And although the invention is illustrated as applied to a self propelled vehicle, it is to be understood that certain of the objects can be accomplished with any power driven unit having a rotatable shaft and braking means therefor and that it is not intended to limit the invention to the exact constructions and combinations shown and described as certain features thereof are of more general application and as various modifications within the scope of the appended claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. In a casing structure enclosing a power driven rotary element and having one wall thereof provided with an opening therethrough aiTording access' to an opposed portion of said element, a bearing housing removably fixed in said opening in coaxial alignment with said element through a detachable connection with a portion of said wall adjacent said opening, a shaft withdrawably-journaled in said bearing housing with its inner end disposed in withdrawable power transmitting relation to said power driven element and with its other end projecting outward from said housing, expansible brake means detachably secured to anouter portion of said housing in concentric relation to said shaft, and a brake drum fixed to Said kshaft and positioned thereby in externally telescoped, cooperative'relation to said expansible brake means.

2. In combination with a casing structure enclosing a power driven rotary element, a rotatable shaft withdrawably cooperatively engaging said element and extending outwardly through said casing structure, means removably mounted in said casing and rotatably supporting said shaft, said means having a portion thereof extending through and beyond the outer wall of said casing, expansible friction means detachably supported on the outwardly extending portion of said shaft supporting means, and a brake drum fixed to said shaft and positioned thereby in externally telescoped, cooperative relation to said expansible brake means.

3. In a casing structure enclosing a power driven rotary element and having one wall thereof provided with an opening therethrough affording access to an opposed portion of said element, a bearing housing removaby rxed in said opening in coaxial alignment with said element through a detachable connection with a portion of said Wall adjacent said opening, a shaft withdrawably journaled in said bearing housing with its inner Yend disposed in withdrawable power transmitting enclosing a power driven rotary element, a rotatable shaft withdrawably cooperatively .engaging said element and extending outwardly through said casing structure, a unitary structure com=v prising a bearing means removably mounted in said wall in supporting relation to said shaft and having a portion thereof projecting outward from said wall, and comprising an expansible brake means detachably xed to the projecting portion of said bearing means, and a brake drum fixed to said shaft and positioned thereby in externally telescoped, cooperative relation to said expansible brake means.

5. In'combination with a casing structure enclosing a power driven rotary element, a rotatable shaft withdrawably cooperatively engaging said element and extending outwardly through said casing structure, a unitary structure comprising a bearing means removably mounted in said wall in supporting relation to said shaft and having a portion thereof projecting outward from said wall, an expansible brake means de tachably fixed to the projecting portion of said bearing means, and comprising means supported by said bearing and brake means operable to actuate the latter, a brake drum fixed to said shaft and positioned thereby in externally telescoped, cooperative relation to said expans'ible brake means, and an elongated housing detachably mounted on said wall of said casing in axially fixed enclosing relation to said shaft. y

6. In combination with a casing structure enclosing a power driven rotary element, a rotatable shaft withdrawably cooperatively engaging said element and extending through and beyond a wall of said casing structure, a unitary structure comprising a bearing means removably mounted in said wall in supporting relation to said shaft and having a portion thereof projecting outward from said wall, expansible brake means detachably xed to the projecting portion of said bearing means, and comprising means operable to actuate said expansible brake means, a brake drum xed to said shaft and positioned thereby in externally telescoped, cooperative relation to said expansible brake means, and an eongated housing detachably mounted on said wallof said casing in axially xed enclosing relation to said shaft, whereby said elongated housing, shaft and brake drum may be separated as a unit from said casing structure to thereby expose said expansible brake means, actuating means and bearing means.

'7. In a motor vehicle having an engine and traction means for propelling same, and having means including diiferential gearing for transmitting power from said engine to said traction means, the combination comprising a casing structure enclosing the differential gearing, a pair of elongatedy axle housings detachably secured to opposite sides of said casing structure, an axle shaft rotatably mounted in each of said axle housings in axially xed relation thereto, said shaft having one endY thereof withdrawably cooperatively engaging an element of said gearing, means rotatably supporting said axle shafts including an elongated bearing structure removably disposed in each of said opposite side walls of said casing structure and extending into said axle housing, an expansible brake means detachably flxedto the extending portion of each of said bearing structures, actuating means for each of said brakes removably supported by said brake and bearing structure, a brake drum nonrotatably xed to each of said axles and positioned thereby 7 8 in externally telescoped, cooperative relation to REFERENCES CITED said brake means and a Wheel nomotatably The folowing references are of record in the secured to each of said axle shafts at the end me of this paient: portion thereof remote from said casing struc- UNITED STATES PATENTS ture.

Number Name Date LOUIS JACOBI- 1,400,170 Kraft Dec. 13, 1921 1,946,093 Morgan Feb. 6, 1934 2,247,668 Rosenthal July 1, 1941

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